Thesis - University of Michigan. / Reprinted from the Journal of wildlife management, vol. 5, no. 2, April, 1941. Bibliography: p. 157-158.

Seventy-eight harbour porpoises, Phocoena phocoena, (33 females, 45 males) were obtained from the summer (June-September) cod fishery incidental-by-catch in the Gulf of St. Lawrence, and examined for the presence of cranial sinus nematodes. This is the first quantitative and in-depth study of the distribution of Stenurus minor (Kuhn, 1829) Baylis and Daubney, 1925 in the cranium of by-caught harbour porpoises. Stenurus minor was present in the cranial sinuses of all adult porpoises ($>$1yr, n = 66, x = 2362, range 87-8920) and absent in all young-of-the-year ($<$1yr, n = 12). Only fifth-stage worms were observed and these were equally distributed between the right and left side ot the skull (mean intensity = 1158 and 1213 in the left and right side, respectively). Female S. minor were predominant (1:1.8 sex ratio). Mean intensity of S. minor was similar among all infected porpoises, suggesting an annual loss and recruitment of this parasite. Parasite load had no apparent effect on porpoise body condition (measured as % blubber weight of carcass). No gross lesions associated with the presence of numerous S. minor in the cranial sinuses, were observed. There was an inverse relationship between the intensity of S. minor and mean worm-length, suggestive of a "crowding effect". Mean worm-length in lightly infected porpoises was 17.8 $ pm$ 0.2 mm and 16.1 $ pm$ 0.2 mm in heavily infected animals. Possible life-cycles and modes of transmission are examined in light of our findings. The absence of S. minor in porpoises less than 1 year old suggests heteroxenous transmission of this parasite, via an intermediate host in the food chain. Transmammary and or transplacental transmission is unlikely.

Thesis (Ph. D.)--Virginia Polytechnic Institute, 1953. / Vita. Abstract. Includes bibliographical references (leaves 30-32). Also available via the Internet.

The distribution and abundance of terrestrial snails which inhabit the Rocky Mountain bighorn sheep (Ovis canadensis Canadensis Shaw) ranges in the East Kootenay region of British Columbia were related to edaphic and climatic factors. Emphasis was placed upon those snail species which have been implicated as intermediate hosts of the sheep lungworm, Protestrongylus stilesi Dikmans. Retinella electrina (Gould), Euconulus fulvus (Muller), and Vitrina alaskana Dall were found to be widely distributed on all ranges and were present in all but the driest plant communities. On low elevation ranges, Euconulus is the most abundant but Retinellai.is the most widely distributed. In alpine regions, however, Vitrina is the dominant species. These hydrophilic species were found mainly on organic soils under leaf litter or logs in aspen and coniferous forest communities where moisture conditions were suitable. The relatively xerophilic species, Vallonia cyclophorella (Sterki), Gastrocopta holzingeri Sterki, and Pupilla muscorum (L.) are restricted to the dry, sandy soils of the bunchgrass communities, where they live under rocks. Of these species, Vallonia is the most abundant, but on the Columbia Lake range, Pupilla, which is restricted to this range, is almost as numerous. The clay and silt soils of the bitterbrush communities appear to be unsuitable for the survival of any snails. Wide temperature and moisture fluctuations, resulting in part from soil texture, appear to be the main factors limiting the occurrence of snails in these sites. With the possible exception of Vitrina and Pupilla, the distribution and abundance of snails on the East Kootenay sheep ranges can not be explained by variations in soil calcium, even though calcium was shown to affect reproductive and growth rates. Vallonia and Pupilla appear to be the most suitable intermediate hosts for sheep lungworm. However, no infected snails were found on any of the ranges and it was established that snails live in a habitat which is inaccessible to sheep. This indicates that terrestrial snails may not play a role in the life cycle of sheep lungworm in the East Kootenay region of B.C. / Science, Faculty of / Zoology, Department of / Graduate

No description available.

Studies were made of the effects of Vitamin A supplementation on the course of artificially induced lungworm infection in calves. Vitamin A deficient, Jersey bull calves, were infected with 2,000 D. viviparus larvae and supplemented with either 2 ug/lb/day or 60 ug/lb/day of Vitamin A. [...]

No description available.

Thesis (Ph. D.)--University of Missouri--Columbia, 1997. / "May 1997." Typescript. Vita. Includes bibliographical references (leaves 173-184). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri--Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves : 173-184). Also available on the Internet.

Protostrongylus stilesi, the parenchymal lungworm, has been attributed an important role in the widespread respiratory diseases of the Rocky Mountain bighorn sheep (Ovis canadensis canadensis). This study was conducted to delineate some of the immunologic and non-specific interactions between parasite and host. A procedure was developed for- the immunochemical quantitation of the ovine immunoglobulins IgG(1), IgG(2) and IgM and for the semi-quantitative analysis of IgA. This technique obviated, the preparation of highly specific antisera required for single radial immunodiffusion. The lungworm did not appear to be a significant part of the total antigenic environment of infected animals since no relationship between immunoglobulin levels and parasite activity was detected. Genetic influences were suggested in the levels of IgG(2) which remained at a relatively constant level characteristic of individual animals. The seromucoids were evaluated as correlates of the inflammatory reaction to parasitism. These proteins were useful in detecting changes in parasite activity and bacterial infection. Gastrointestinal disorders associated with severe scouring were accompanied by the disappearance of circulating orosomucoid (α-1 acid glycoprotein). The loss of this low molecular weight protein appeared to be related to vascular leakage. Lungworm infections induced the appearance of homocytotropic antibodies which could be detected in vitro by their ability to sensitize peripheral polymorphonuclear leucocytes for adherence to the larval cuticle. The elution of this antibody from sensitized cells and the inhibition of the adherence reaction with specific antiserum suggested that the reaction was mediated at least partly by IgG(1). The adherence reaction was used to assay homocytotropic activity of serum from infected animals (washed-cell test). This test was correlated with the ability of sera to sensitize skin for anaphylaxis. The effective hypersensitive response, accounting for both sensitizing and blocking activity, was determined by exposing normal cells to larvae in a medium containing serum (decomplemented-serum test). The results of this test paralleled inflammatory changes in parasitized animals, monitored by the levels of serum orosomucoid. Using this method, levels of homocytotropic and blocking antibodies were measured throughout the annual parasite cycle. Preliminary observations indicated that immunogenic inflammation, associated with the "spring rise" and "self cure," resulted from a shift in a dynamic balance between competing antibodies rather than a proportionate increase in homocytotropic activity. The response of peripheral lymphocytes to the presence of larvae or larval extracts was cursorily examined. Although ovine lymphocytes did not respond well enough in culture to draw definitive conclusions, the presence of larval extracts appeared to have a detrimental effect on cell survival and transformation. Even in the presence of EDTA, minute amounts of antibody sensitized lymphocytes for adherence to the larval cuticle. Sera from a wide variety of sources had an inhibitory effect on this reaction. Treatment of larvae with neuraminidase and high concentrations of NaCl engendered improved adherence. This suggested that Protostrongylus had adopted mechanisms similar to the trophoblast or the neoplastic cell which allegedly evade immunologic recognition with a strongly anionic coat. These aspects are discussed in terms of the possible role of Protostrongylus in respiratory diseases of the bighorn sheep, and the exploitation of molecular mechanisms in the control of parasitic diseases. / Land and Food Systems, Faculty of / Graduate